Deposition methods

ABSTRACT

A deposition method includes positioning a substrate within a deposition chamber defined at least in part by chamber walls. At least one of the chamber walls comprises a chamber surface having a plurality of purge gas inlets to the chamber therein. A process gas is provided over the substrate effective to deposit a layer onto the substrate. During such providing, a material adheres to the chamber surface. Reactive purge gas is emitted to the deposition chamber from the purge gas inlets effective to form a reactive gas curtain over the chamber surface and away from the substrate, with such reactive gas reacting with such adhering material. Further implementations are contemplated.

BACKGROUND OF THE INVENTION

Semiconductor processing in the fabrication of integrated circuitrytypically includes the deposition of layers on semiconductor substrates.Exemplary processes include physical vapor deposition (PVD), andchemical vapor deposition (CVD) which herein includes atomic layerdeposition (ALD). With typical ALD, successive mono-atomic layers areadsorbed to a substrate and/or reacted with the outer layer on thesubstrate, typically by successive feeding of different precursors tothe substrate surface.

Chemical and physical vapor depositions are typically conducted withinchambers or reactors which retain a single substrate upon a wafer holderor susceptor. The chambers include internal walls and other internalcomponents which can undesirably have deposition product depositedthereupon in addition to the substrate. This is particularly problematicin ALD and other CVD processes, yet can also occur with PVD chambers.One existing method of protecting or preserving the internal chamberwalls and other components is to shield such from the depositionmaterial with one or more removable liners or shields. The liners mightbe received immediately adjacent or against the internal chamber wallsor other surfaces. Alternately, the liners might be displaced from thewall or other surfaces, thereby defining an appreciably reduced volumechamber, or subchamber, within which the substrate is received fordeposition. One advantage of using liners and shields is that they canbe periodically replaced with new or cleaned liners, thereby extendingthe life of the deposition chambers and components therein. Further andregardless, the spent liners and shields can typically be removed andreplaced much more quickly than the time it would take to clean theinternal chamber walls and other components at given cleaning intervals.

An exemplary ALD method includes feeding a single vaporized precursor toa deposition chamber effective to form a first monolayer over asubstrate received therein. Thereafter, the flow of the first depositionprecursor is ceased and an inert purge gas is flowed through the chambereffective to remove any remaining first precursor which is not adheringto the substrate from the chamber. Subsequently, a second vaporprecursor different from the first is flowed to the chamber effective toform a second monolayer on/with the first monolayer. The secondmonolayer might react with the first monolayer. Additional precursorscan form successive monolayers, or the above process can be repeateduntil a desired thickness and composition layer has been formed over thesubstrate.

It is a desired intent or effect of the purging to remove gas moleculesthat have not adsorbed to the substrate or unreacted gas or reactionby-products from the chamber to provide a clean reactive surface on thesubstrate for the subsequent precursor. In the context of this document,a reaction by-product is any substance (whether gas, liquid, solid ormixture thereof) which results from reaction of any deposition precursorflowing to the chamber and that is not desired to be deposited on thesubstrate. Further in the context of this document, an intermediatereaction by-product or reaction intermediate by-product is a reactionby-product formed by less than complete reaction of a precursor to forma desired monolayer on the substrate. Where there is a great degree ofvarying topography and/or there are high aspect ratio features on thesubstrate, it can be difficult to move the unreacted gases or reactionby-products from deep within openings for ultimate removal from thechamber. Further, certain reaction by-products, particularlyintermediate reaction by-products, may not be gaseous and may notcompletely react to form gaseous reaction by-products in the typicalshort precursor pulse times. Accordingly, the purge gas pulse may not beeffective or sufficient in removing such intermediate reactionby-products from the substrate and chamber.

For example, consider that in an atomic layer deposition of titaniumnitride using TiCl₄ and NH₃, the desired deposition product is TiN withHCl gas being the desired principle gaseous by-product. Consider alsothat there might be reaction intermediate by-products which might, evenif gaseous, be difficult to remove from substrate openings. Further, ifcertain reaction intermediate by-products are solid and/or liquid phaseprior to HCl formation, complete removal can be even more problematicwhere less than complete reaction to TiN and HCl occurs.

Consider also the atomic layer deposition of Al₂O₃ usingtrimethylaluminum (TMA) and ozone as alternating deposition precursors.Apparently in such deposition, achieving an effective ozone precursorfeed can be somewhat of a challenge due to the limited lifetime of ozonewithin the chamber. Specifically, an ozone molecule is an inherentlyunstable, reactive form of oxygen which can rapidly dissociate and/orcombine with another ozone molecule to form three O₂ molecules.Regardless, a desired goal in the ozone feed is adsorption of oxygenatoms from the O₃ to the surface of the substrate with O₂ as thereaction by-product which is driven off. Of course, the O₂ which formsdeep within openings on the substrate has to be removed therefrom whilemore O₃ needs to get into the openings to form a complete monolayer ofoxygen atoms adhering to the substrate. In other words, the O₂ whichforms is trying to get out while more O₃ is trying to get in.

While the invention was motivated in addressing the above issues andimproving upon the above-described drawbacks, it is in no way solimited. The invention is only limited by the accompanying claims asliterally worded (without interpretative or other limiting reference tothe above background art description, remaining portions of thespecification or the drawings) and in accordance with the doctrine ofequivalents.

SUMMARY

In one implementation, a deposition method includes positioning asubstrate within a deposition chamber defined at least in part bychamber walls. At least one of the chamber walls comprises a chambersurface having a plurality of purge gas inlets to the chamber therein. Aprocess gas is provided over the substrate effective to deposit a layeronto the substrate. During such providing, a material adheres to thechamber surface. Reactive purge gas is emitted to the deposition chamberfrom the purge gas inlets effective to form a reactive gas curtain overthe chamber surface and away from the substrate, with such reactive gasreacting with such adhering material.

In one implementation, a deposition method includes positioning asubstrate within a deposition chamber defined at least in part bychamber walls. The deposition chamber has a component received thereininternally of the chamber walls. The component has a surface exposed tothe chamber. The surface has a plurality of purge gas inlets to thechamber therein. A process gas is provided over the substrate effectiveto deposit a layer onto the substrate. During such providing, a materialadheres to the chamber surface. Reactive purge gas is emitted to thedeposition chamber from the purge gas inlets effective to form areactive gas curtain over the component surface within the depositionchamber and away from the substrate, with such reactive gas reactingwith such adhering material.

Further implementations are contemplated.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a diagrammatic sectional view of a chemical vapor depositionapparatus usable in accordance with an aspect of the invention.

FIG. 2 is an enlarged sectional view of a portion of a chemical vapordeposition apparatus usable in accordance with an aspect of theinvention

FIG. 3 is an enlarged sectional view of a portion of an alternateembodiment chemical vapor deposition apparatus usable in accordance withan aspect of the invention.

FIG. 4 is an enlarged sectional view of a portion of another alternateembodiment chemical vapor deposition apparatus usable in accordance withan aspect of the invention.

FIG. 5 is a diagrammatic sectional view of an alternate chemical vapordeposition apparatus usable in accordance with an aspect of theinvention.

FIG. 6 is a diagrammatic sectional view of another alternate chemicalvapor deposition apparatus usable in accordance with an aspect of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

By way of example only, FIG. 1 depicts an exemplary embodiment chemicalvapor deposition apparatus 10 usable in accordance with methodicalaspects of the invention. Any other apparatus, whether existing oryet-to-be-developed, could of course also/alternatively be utilized.Apparatus 10 includes a chamber 15 defined at least in part by chamberwalls 12, 14 and 16. Wall or walls 12 comprise a chamber sidewall, wallor walls 14 comprise a chamber base wall, and wall or walls 16 comprisea chamber top wall. Chamber 15 includes at least one process chemicalinlet 18 thereto, and an outlet 20 feeding therefrom. Outlet 20 feeds toa foreline 22 for connection with a vacuum pump (not shown). A suitablesubstrate holder 24 is provided within chamber 15. Such includes somesuitable support structure 26, and is illustrated as receiving asubstrate 25, preferably a semiconductor substrate, thereatop. In thecontext of this document, the term “semiconductor substrate” or“semiconductive substrate” is defined to mean any constructioncomprising semiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials thereon), and semiconductivematerial layers (either alone or in assemblies comprising othermaterials). The term “substrate” refers to any supporting structure,including, but not limited to, the semiconductive substrates describedabove. Process gas inlet 18 is diagrammatically shown as feeding to ashowerhead 27 associated with a lid of the apparatus for providing oneor more process gasses to substrate 25 for deposition of a materialthereon.

Chamber sidewalls 12 and chamber base walls 14 are depicted as havingchamber surfaces having a plurality of purge gas inlets 28 to thechamber formed therein. The depicted purge gas inlets are separate ordifferent from process gas inlet 18. A plenum chamber 30 is formedbehind walls 12, 14 and is fed by a purge gas inlet passageway 32, whichis thereby in fluid communication with purge gas inlets 28. In preferredimplementations, walls 12, 14 are constructed of highly porousmaterials, such as sintered metal particles or fibers, low densityteflon, or other synthetic organic and/or inorganic materials, and byway of example only. Material selection would ideally be based onintended process chemistries. Further by way of example only, walls 12,14 might be constructed to form a screen-like mesh, with pores/outlets28 being defined by interstices thereof. The pore sizes of the materialwould depend on material characteristics and deposition processcharacteristics. Exemplary pore sizes include from tens of microns totens of Angstroms. Further by way of example only, walls 12, 14 mightcomprise an essentially solid, hard, planar wall surface having aplurality of openings 28 drilled or otherwise formed therein, such as isshown. In the FIG. 1, the chamber surface having the plurality of purgegas inlets 28 is essentially formed on and constitutes both the chambersidewall and the chamber base wall. Further by way of example only, suchpurge gas inlets might alternately be included only on either thesidewall or base wall, and the chamber surface can be considered asbeing only a portion or portions thereof. Further, purge gas inlet'smight also be provided on a top wall of chamber 15, for example inmanners described herein, and in accordance with U.S. patent applicationSer. No. 09/805,620 filed on Mar. 13, 2001, entitled “Chemical VaporDeposition Apparatus and Deposition Methods”, listing Craig M. Carpenterand Ross S. Dando as inventors, and which is hereby incorporated byreference.

As depicted, the purge gas inlets are substantially uniformlydistributed over the chamber surface over which such are received.Further and/or additionally, purge gas inlets 28 might all be ofsubstantially constant size, or of at least two inlet sizes. In onepreferred embodiment, at least some of purge gas inlets 28 which arefurther from chamber outlet 20 are larger than at least some of thepurge gas inlets 28 which are closer to chamber outlet 20. Such providesone manner by which, if desired, a greater volumetric flow of purge gascan be provided proximate the respective wall surfaces further fromchamber outlet 20 than closer thereto. A purge gas outlet passageway 36is depicted as extending from purge gas inlet passageway 32, 30 toforeline 22, thereby by-passing the plurality of purge gas inlets 28.Appropriate valving (not depicted) might, of course, be associated withpassageway 36 or any other of the depicted passageways/inlets/outlets. Apurge gas outlet passageway might be included to assist in control ofthe flow rate and pressure within plenum chamber 30 and, thereby, alsofrom purge gas inlets 28.

By way of example only, FIGS. 2, 3 and 4 depict exemplary alternatepurge gas inlets 28. For example, FIG. 2 depicts an exemplary chamberwall 40 having a chamber surface 42 having a plurality of purge gasinlets 28 a received therein. Such are depicted as comprising openingsextending from a purge gas inlet passageway 44 within wall 40 and whichwould be exposed to a deposition chamber, for example deposition chamber15. Accordingly, the exemplary depicted purge gas inlets 28 a in suchembodiment (and inlets 28 in the FIG. 1 embodiment) are configured fordischarging purge gas to the chamber in a direction which issubstantially transverse, for example in a direction “A” to chambersurface 42. In the context of this document, “a direction substantiallytransverse” is defined to mean anything from perfectly perpendicular(90°) to the chamber surface to, but not including, 45° from the chambersurface.

FIG. 3 depicts an exemplary alternate embodiment chamber wall 40 b. Likenumerals from the FIG. 2 described embodiment are utilized whereappropriate, with differences being indicated by the suffix “b” or withdifferent numerals. Purge gas inlets 28 b are depicted as beingconfigured for discharging purge gas to the chamber in a directionsubstantially along chamber surface 42 b. In the context of thisdocument, “substantially along” means from 45° to parallel with thechamber surface. In the depicted exemplary FIG. 3 embodiment, chambersurface 42 b is provided (or alternately considered, purge inlets 28 bare provided) with deflectors/diverters/ramps 43 angled at an exemplary40° from surface 42 b for achieving such purge gas discharging generallyin a direction “B”.

Further by way of example only, FIG. 4 depicts yet another embodimentconfiguration for purge gas inlets 28 c. Like numerals from the FIGS. 2and 3 described embodiments are utilized where appropriate, withdifferences being indicated with the suffix “c”, or with differentnumerals. In FIG. 4, deflectors 43 c are depicted as curving or rampingto extend a portion thereof essentially parallel along surface 42 c.

In accordance with an aspect of the invention, one preferred depositionmethod positions a substrate within a deposition chamber defined, atleast in part, by chamber walls such as, by way of example only,substrate 25 positioned within chemical vapor deposition apparatus 10.At least one of the chamber walls comprises a chamber surface having aplurality of purge gas inlets to the chamber. For example, any multipleset or subset of purge gas inlets 28, in conjunction with the FIG. 1described embodiment, depict such a plurality of purge gas inlets.

A process gas (i.e., in one or more flowings) is provided over thesubstrate effective to deposit a layer onto the substrate. In thedepicted exemplary FIG. 1 embodiment, one or more process gasses couldbe provided via process gas inlet 18 to showerhead 27. During provisionof the process gas effective to deposit a layer on the substrate, somematerial adheres to the chamber surface.

A reactive purge gas is emitted to the deposition chamber from purge gasinlets effective to form a reactive gas curtain over the chamber surfaceand away from the substrate, with such reactive gas reacting with theadhering material. In one implementation, the reactive gas flowingoccurs after depositing the layer on the substrate. In oneimplementation, the reactive gas flowing occurs during the process gasflowing. In one implementation, the reactive purge gas is different incomposition from all of the process gas. Further, the reactive gas mayor may not be capable under conditions of the reactive gas flowing ofreaction with the exposed layer which has or is being deposited.

By way of example only, the adhering material might be reactive with oneor a multiple of the deposition precursors. In such event, it might bedesirable to remove such adhering material from the substrate so it willnot react with subsequent flowing precursor, or at least in some waypassivate such adhering material to preclude its reaction withsubsequently flowing deposition precursors. Further by way of exampleonly, the adhering material might result, in part, from the reaction ofdeposition precursor with material of the chamber surface, thus formingmaterial adhering thereto. Such might constitute a monolayer in ALDincluding eventually considerably thicker layers from the successiveformation of repeated monolayers.

By way of example only, an exemplary adhered material might compriseoxygen atoms adhering to a metal chamber surface. Such could manifest bythe feeding of ozone in any of the above-described exemplary processesinvolving the deposition of Al₂O₃. Alternately by way of example only,such might encompass any of TiCl₂, TiCl₃ and NH₃ complexes with respectto TiCl₄ and NH₃ deposition precursor flows.

In one aspect, the reactive gas reacts to modify the composition of theadhering material, with such modified composition material adhering tothe chamber surface. By way of example only, and where the adheringmaterial comprises Al—(CH₃)₂, an exemplary reactive gas would beactivated hydrogen to modify the adhering material composition to Al,which still adheres to the chamber surface.

In one aspect, the reactive gas reacts to effectively remove the adheredmaterial, and any reaction by-product thereof, from adhering to thechamber surface. For example and by way of example only, where theadhering material comprises TiCl, TiCl₂ and/or TiCl₃, an exemplaryreactive gas includes Cl₂, which would effectively etch or otherwisevaporize the adhering material from the substrate and be exhausted fromthe chamber.

The conditions (i.e., temperature, pressure, flow rate, etc.) of thereactive gas flowing can be optimized by the artisan and are nototherwise particularly germane or preferred to any aspect of theinvention. By way of example only, such conditions might be the same as,or different from, any of a first precursor gas flow, a second precursorgas flow and/or inert purge gas flow. In one aspect, the reactive gasflow is plasma-enhanced, for example either by plasma generation withinthe chamber, plasma generation remote of the chamber, or both.

The particular reactive gas selected, whether a single constituent or amixture of constituents, will depend as a minimum upon at least someportion or component of the adhering material which will be capable ofreaction with the reactive gas under conditions of the reactive gasflowing. By way of example only, possible reactive: gases componentsinclude Cl₂, O₂ and H₂. For example and by way of example only where theadhering material comprises oxygen atoms, such might be removed in thepresence of O₂ to form ozone and/or with H₂ to form H₂O which isexhausted from the chamber.

In one preferred methodical aspect of the invention, the reactive purgegas is emitted to the chamber in a direction substantially transverse tothe chamber surface associated with the purge gas inlets and, in oneembodiment, is also effective to form the reactive gas curtain tocomprise substantially turbulent gas flow proximate the chamber surface.In another preferred embodiment, the purge gas emitting to the chamberis in a direction substantially along the chamber surface and, in oneembodiment, is additionally effective to form the reactive gas curtainto comprise substantially laminar gas flow proximate the chambersurface. In some operating regimes, viscous or turbulent flow may bedesired proximate the surface being protected, whereas in other regimeslaminar flow might be desired.

In one embodiment, the purge gas emitting comprises emitting a greatervolume of purge gas from at least some purge gas inlets located furtherfrom the chamber outlet than from at least some purge gas inlets locatedcloser to the chamber outlet. Such might be accommodated by providinglarger outlets further from the chamber outlet than closer to thechamber outlet, and/or by providing greater flow and/or pressure to thepurge gas inlets which are located further/furthest from the chamberoutlet. Preferred depositions include chemical vapor deposition,including atomic layer deposition.

The above-described exemplary embodiments/implementations wereessentially in conjunction with chamber walls which effectively define amaximum internal volume within a deposition apparatus 10. FIG. 5 depictsan exemplary alternate chemical vapor deposition apparatus 10 a. Likenumerals from the FIG. 1 described embodiment are utilized whereappropriate, with differences being indicated with the suffix “a”, orwith different numerals. Chemical vapor deposition apparatus 10 aincludes a chamber liner apparatus 50 forming a deposition subchamber 17within chamber 15 a. Chamber liner apparatus 50 comprises subchambersurfaces 51 having a plurality of purge gas inlets 52 to the subchambertherein. By way of example only, purge gas inlets 52 might be configuredin any of the manners described above, including the depictions withrespect to inlets 28, 28 a, 28 b and 28 c described above. Further,liner apparatus 50 would ideally be configured or fabricated to be aneasily replaceable component of apparatus 10 a. By way of example only,the exemplary FIG. 5 embodiment depicts the various walls of linerapparatus 50 as comprising a retained intertwined, mesh-like materialwhich is fed by a plurality of purge gas inlet passageways 56 forproviding the desired purge gas thereto during deposition. Otherpreferred attributes of the method, for example as described withrespect to FIGS. 1-4 above, can be incorporated with chamber linerapparatus 50.

By way of example only, an alternate exemplary apparatus usable topractice the invention is described with reference to FIG. 6. Likenumerals from the first-described embodiments are utilized whereappropriate, with differences being indicated with the suffix “f”, orwith different numerals. FIG. 6 depicts a chemical vapor depositionapparatus 10 f comprising a deposition chamber 15 f which is at least inpart defined by chamber walls 12 f, 14 f and 16 f. Substrate holder 24 fcomprises support structure 26 f. Such includes a surface or surfaces 70exposed to chamber 15 f and which comprise(s) a plurality of purge gasinlets 75 to chamber 15 f. An exemplary purge gas inlet passageway 77 isshown in communication with support structure 26 f, and accordingly withpurge gas inlets 75. Such purge gas inlets might have any of theattributes described above with respect to the other describedembodiments.

Regardless, and in accordance with another methodical implementation ofthe invention, a deposition method comprises positioning a substratewithin a deposition chamber defined at least in part by chamber walls.The deposition chamber comprises a component received therein internallyof the chamber walls. By way of example only, substrate holder 24 f andits associated support structure 26 f is one exemplary such component.However, any other component is contemplated in accordance withmethodical aspects of the invention. The component comprises a surface,exposed to the chamber, which has a plurality of purge gas inlets to thechamber therein.

A process gas is provided over the substrate effective to deposit alayer onto the substrate. During provision of the process gas effectiveto deposit a layer on the substrate, some material adheres to thechamber surface.

A reactive purge gas is emitted to the deposition chamber from purge gasinlets effective to form a reactive gas curtain over the componentsurface and away from the substrate, with such reactive gas reactingwith the adhering material. Any other attribute as described above withrespect to other methodical implementation of the invention is of coursecontemplated.

Control of the reactive purge gas flow can be through a variety ofmethods, such as an active feedback control loop based on a pressuresensors ported to the purge gas channels and linked to mass flowcontrollers, needle valves, any of various digital valve-type flowcontrollers, line pressure regulators or other existing or yet-to-bedeveloped methods.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A deposition method comprising: positioning a substrate within adeposition chamber defined at least in part by chamber sidewalls, atleast one of the chamber sidewalls comprising a chamber surface;providing a process gas over the substrate effective to deposit a layeronto the substrate; adhering a material to the chamber surface; andwhile the substrate is within the deposition chamber, emitting reactivepurge gas to the deposition chamber effective to form a reactive gascurtain over the chamber surface and away from the substrate, with suchreactive gas reacting with such adhering material.
 2. The method ofclaim 1 wherein the emitting occurs after the providing.
 3. The methodof claim 1 wherein the reactive purge gas is different in compositionfrom all said process gas.
 4. The method of claim 1 wherein the reactivepurge gas reacts to modify composition of the adhering material, withsuch modified composition material adhering to the chamber surface. 5.The method of claim 1 wherein the reactive purge gas reacts toeffectively remove such material, and any reaction by-product thereof,from adhering to the chamber surface.
 6. The method of claim 1comprising emitting the reactive purge gas to the chamber in a directionsubstantially transverse to the chamber surface and effective to formthe reactive gas curtain to comprise substantially turbulent gas flowproximate the chamber surface.
 7. The method of claim 1 comprisingemitting the reactive purge gas to the chamber in a directionsubstantially along the chamber surface and effective to form thereactive gas curtain to comprise substantially laminar gas flowproximate the chamber surface. 8-10. (canceled)
 11. The method of claim1 wherein the deposition chamber includes an outlet therefrom, theemitting comprises emitting a greater volume of reactive purge gas somelocations further from the chamber outlet than at some locations closerto the chamber outlet.
 12. (canceled)
 13. The method of claim 1 whereinthe chamber sidewall having the chamber surface comprises a surface of achamber liner apparatus forming a deposition subchamber within thechamber.
 14. The method of claim 1 comprising chemical vapor deposition.15. The method of claim 14 comprising atomic layer deposition.
 16. Themethod of claim 1 wherein the reactive purge gas is plasma enhanced. 17.The method of claim 1 wherein the reactive purge gas is plasma enhancedby plasma generation within the chamber.
 18. The method of claim 1wherein the reactive purge gas is plasma enhanced by plasma generationremote of the chamber.
 19. A deposition method comprising: positioning asubstrate within a deposition chamber defined at least in part bychamber walls, at least one of the chamber walls comprising a chambersurface; providing a process gas over the substrate effective to deposita layer onto the substrate; adhering a material to the chamber surface;and during such providing, emitting reactive purge gas to the depositionchamber effective to form a reactive gas curtain over the chambersurface and away from the substrate, with such reactive purge gasreacting with such adhering material, the reactive purge gas beingdifferent in composition from all said process gas.
 20. The method ofclaim 19 comprising emitting the reactive purge gas to the chamber in adirection substantially transverse to the chamber surface and effectiveto form the reactive gas curtain to comprise substantially turbulent gasflow proximate the chamber surface.
 21. The method of claim 19comprising emitting the reactive purge gas to the chamber in a directionsubstantially along the chamber surface and effective to form thereactive gas curtain to comprise substantially laminar gas flowproximate the chamber surface. 22-24. (canceled)
 25. The method of claim19 wherein the deposition chamber includes an outlet therefrom, theemitting comprises emitting a greater volume of reactive purge gas atsome locations further from the chamber outlet than at some locationscloser to the chamber outlet.
 26. (canceled)
 27. The method of claim 19wherein the chamber wall having the chamber surface comprises a surfaceof a chamber liner apparatus forming a deposition subchamber within thechamber.
 28. The method of claim 19 comprising chemical vapordeposition.
 29. The method of claim 28 comprising atomic layerdeposition.
 30. The method of claim 19 wherein the reactive purge gas isplasma enhanced.
 31. The method of claim 19 wherein the reactive purgegas is plasma enhanced by plasma generation within the chamber.
 32. Themethod of claim 19 wherein the reactive purge gas is plasma enhanced byplasma generation remote of the chamber. 33-45. (canceled)
 46. Adeposition method comprising: positioning a substrate within adeposition chamber defined at least in part by chamber walls, thedeposition chamber comprising a component received therein internally ofthe chamber walls, the component comprising a surface exposed to thechamber, providing a process gas over the substrate effective to deposita layer onto the substrate; adhering a material to the componentsurface; during such providing, emitting reactive purge gas to thedeposition chamber effective to form a reactive gas curtain over thecomponent surface within the deposition chamber and away from thesubstrate, with such reactive gas reacting with such adhering material,the reactive purge gas being different in composition from all saidprocess gas.
 47. The method of claim 46 wherein the component comprisesa portion of a substrate support received internally of the chamberwalls.
 48. The method of claim 46 comprising emitting the reactive purgegas to the chamber in a direction substantially transverse to thesurface and effective to form the reactive gas curtain to comprisesubstantially turbulent gas flow proximate the surface.
 49. The methodof claim 46 comprising emitting the reactive purge gas to the chamber ina direction substantially along the surface and effective to form thereactive gas curtain to comprise substantially laminar gas flowproximate the surface.
 50. The method of claim 46 wherein the depositionchamber includes an outlet therefrom, the emitting comprises emitting agreater volume of reactive purge gas at some locations further from thechamber outlet than at some locations closer to the chamber outlet. 51.(canceled)
 52. The method of claim 46 comprising chemical vapordeposition.
 53. The method of claim 52 comprising atomic layerdeposition.
 54. The method of claim 46 wherein the reactive purge gas isplasma enhanced.
 55. The method of claim 46 wherein the reactive purgegas is plasma enhanced by plasma generation within the chamber.
 56. Themethod of claim 46 wherein the reactive purge gas is plasma enhanced byplasma generation remote of the chamber.